poprawil?

app/src/main/assets/css/styles.css

@@ -265,7 +265,7 @@ body {
 }
 
 .progress-bar {
-  width: 120px;
+  width: 100%;
   height: 8px;
   background-color: #e2e8f0;
   border-radius: 4px;

app/src/main/assets/js/czytanie.js

@@ -21,7 +21,7 @@
   const readViewport  = document.getElementById('read-viewport')
   const readTextEl    = document.getElementById('read-text')
   const nextLineBtn   = document.getElementById('next-line-btn')
-  const progressBar   = document.getElementById('read-progress-bar-inner')
+  let progressBar = null
 
   // ── Load text list from dyktanda.json ────────────────────────────────────
   fetch('json/dyktanda.json')
@@ -132,6 +132,7 @@
 
   function updateProgressBar() {
     const progress = maxOffset > 0 ? (yOffset / maxOffset) * 100 : 100
-    progressBar.style.width = `${progress}%`
+    if (!progressBar) progressBar = document.getElementById('read-progress-bar-inner')
+    if (progressBar) progressBar.style.width = `${progress}%`
   }
 })()

app/src/main/assets/js/mnozenie.js

@@ -8,7 +8,7 @@
   const problemEl     = document.getElementById('problem')
   const answerEl      = document.getElementById('answer')
   const feedbackEl    = document.getElementById('feedback')
-  const progressInner = document.getElementById('progress-inner')
+  let progressInner = null
   const progressLabel = document.getElementById('progress-label')
   const scoreLabel    = document.getElementById('score-label') // This element is removed, but we might re-purpose the logic
   const summaryText   = document.getElementById('summary-text')
@@ -99,7 +99,8 @@
 
   function updateBar() {
     const pct = st.total > 0 ? Math.round((st.solved / st.total) * 100) : 0
-    progressInner.style.width = pct + '%'
+    if (!progressInner) progressInner = document.getElementById('progress-inner')
+    if (progressInner) progressInner.style.width = pct + '%'
     progressLabel.textContent = `${st.solved}/${st.total}`
     // scoreLabel is removed, so we comment this out
     // scoreLabel.textContent = `✔ ${st.score}`